1. Field of the Invention
The present invention relates to animal body parts calibration phantoms, and in particular to a thyroid calibration phantom for calibration of radiation detection equipment used to measure the uptake of radioactive tracer by the thyroid gland.
2. Description of the Prior Art
Conventional thyroid phantoms employ liquid solutions or dispersions of radio-iodine as the tracer material. Radio-iodine is an extremely toxic material. Accordingly, spills or leaks of such material are hazardous to the health of laboratory personnel.
One such thyroid phantom is manufactured and sold by Radiology Support Devices Inc. of Long Beach, Calif. This device comprises a hollow-shell synthetic resin material in the three-dimensional characteristic butterfly-shape of the thyroid. Posterior ports are provided for filling the device with a liquid solution/dispersion of radio-iodine or the like. A further drawback of this device is that it cannot be completely filled with the liquid. As a result an air bubble is formed which affects the accuracy of the device. Moreover, the device is made to fit snugly into a companion neck phantom which has no capacity to accept other sizes of thyroid phantoms or fat overlay. This presents a problem in calibrating for patients with other than average sized thyroids or heavy patients who have more than the average amount of fat tissue covering their thyroid gland.